Holley Sniper Fuel Injection and Hyperspark Ignition Install Show and Tell

[DrEamer]

I was determined not to mount the coil to the firewall, so I spent a good part of the day fabbing a mount using the coil mounts on my RPM Air-Gap manifold.

 

[MoparCarGuy]

1970GranCoupeCo,​

I noticed your tank has fewer holes in the baffle for anti-slosh. I saw that you ordered the Holley Sniper tank kit. I wonder if Tanks, Inc. (Holley's source vendor) followed what Holley spec'd for the baffle versus there own specs? Hmm.

Tanks, Inc.

 

[1970GranCoupeCo]

Dr Eamer Nice installation of the coil

>Tanks, Inc. (Holley's source vendor) followed what Holley spec'd for the baffle versus there own specs? Hmm.

It is interesting that the fuel tanks are identical except for the number of holes in the baffle. How old is your fuel tank? I bought mine from eBay and the previous owner had bought it in the past but had never gone through with the project so perhaps mine is an older unit therefore older design.

I don't know why there needs to be any holes in the baffle at all because the sides of the baffle don't seal off any fuel so fuel is going to get to the front of the baffle anyway

 

[MoparCarGuy]

Re-watch the video at 02:05 (Note that his mark is made at the clear cap detent which is the #1 spark plug tower, not at the rotor tip location which is 15° BTDC:



This graphic should help everyone see how this works to lock down the distributor with a built-in 15° BTDC timing reference angle.

 

[MoparCarGuy]

Dr Eamer Nice installation of the coil

>Tanks, Inc. (Holley's source vendor) followed what Holley spec'd for the baffle versus there own specs? Hmm.

It is interesting that the fuel tanks are identical except for the number of holes in the baffle. How old is your fuel tank? I bought mine from eBay and the previous owner had bought it in the past but had never gone through with the project so perhaps mine is an older unit therefore older design.

I don't know why there needs to be any holes in the baffle at all because the sides of the baffle don't seal off any fuel so fuel is going to get to the front of the baffle anyway

I just received my tank at the end of February.
The baffle prevents excessive foaming (aeration) of the fuel on acceleration/deceleration. The pump sump obviously keeps the pump submerged very well.

 

[1970GranCoupeCo]

MoparCityGuy,

Nice work on the graphic!!!

Im glad you are on our team...and not a ChebbyCityGuy

 

[MoparCarGuy]

I am glad you posted all the detailed info. It will save others, including me, a lot of time. Kudos!

 

[1970GranCoupeCo]

Still have not driven the car yet (doing a power brake retrofit, Classic Auto Air AC retrofit, and have already installed the subframe connectors) so every morning I start the engine to fine tune the cold start and now it starts right up.

Here are a couple of things that I learned and tweaked in the generic "street/strip" programming.

First check the timing using the Tuning -> System -> Static Timing and run the engine at 15 degrees BTDC to ensure the distributor is installed correctly. If the ignition is switched off the timing will automatically go back to the ignition curve in the program so if your timing light is acting up and you shut off the engine and then start it back up to do the 15 degrees procedure you will need to go back into Tuning -> System -> Static Timing and start over.

When the ignition switch is turned on you can hear the electric fuel pump buzzing and it takes 2.5 seconds for the Engine Control Unit (ECU) computer to boot up and at 2.5 seconds the handheld screen illuminates. Don't try to start the engine for 2.5 seconds (the point where the screen illuminates) otherwise the starter motor will need to crank until the 2.5 second mark.

After the timing is set correctly and everything is running good and you have done a number of warm engine idle sessions to the point where the ECU has learned its warm engine idle fuel MAP make sure to adjust the throttle stop set screw so that the Idle Air Control (IAC) position when the engine is warmed up and idling the IAC value needs to read between 2-10% with the engine running at idle in park without an AC on, if equipped. If the value is 0 the blades need to be closed until it reads between 2-10%, if the value is higher than 10% the blades need to be opened until it reads between 2% and 10%.

So now if the engine is running good when it is warm but the cold starting is not too great there are two things that you can fiddle with to dial it in and that is either "Fuel Prime" or "IAC Startup Position".

Fuel Prime is the feature where the ECU injects a squirt of fuel into the intake manifold before the starter motor is cranked and this shot of gas helps the engine fire off and it can be too much or too little. While you are waiting the 2.5 minutes you can hear the electric fuel pump buzzing and you will hear a quick click from the throttle body when the fuel prime is doing its thing.

-The IAC Startup Position is how far the IAC is commanded to open during the start and how long it will stay open after the start...here is what the book says:
IAC Parked Position (Cranking): This is the position the IAC motor will be at during cranking and immediately after the engine starts. If it is too high, the engine will be at too high of an RPM once it starts. Too low and poor starting will result. Note that this is a temperature based table. The percentage value changed in the handheld offsets this entire curve.
-IAC Startup Hold Time: This is the amount of time that the IAC will remain at the “IAC Parked Position”.
-IAC Startup Decay Time: This is the amount of time for the IAC to decay from the “IAC Parked Position” back to its “Target Idle” position. It is a linear decay


So if the cold start is poor the question is...is it fuel or air that the engine needs?

Here is one way to find out before you fiddle with the program...Give it a double or triple shot of prime and see if it starts better. When the engine is cold the first start of the day turn the key on and wait to hear the Fuel Prime click and then turn the key off and then do a "normal" start by turning the key on and waiting 2.5 seconds then crank the engine. If the double (or triple) shot of prime helped the cold start then go into the program and increase the value 20 percent.

If the engine kicks and then runs slow and rough and then you hear the air noise through the IAC increase as the ECU is telling the IAC to open up and then the engine begins to run better then it is the IAC Parked Position Cranking that needs to be increased and also the IAC Startup Hold Time extended.

Here is a PDF of the complete 76 page installation manual https://documents.holley.com/199r11031r.pdf


So now to keep working on the car!!!

 

[Big AL]

I went with the EZ-efi by Fast on my 70 R/T had it for about two years and no problems
also runs smoother and quick start.

 

[ctaarman]

Just one thought for you: In researching these, I found that there were a number of failures. Likely the cause is the sleek unit package that houses the circuitry right along with the throttle bodies, resulting in electronics that get to cook on top of a hot engine. A 1/4 inch phenolic spacer between the Sniper unit and the intake manifold will provide significant thermal isolation. You will be able to feel the difference in temp, and give some protection. It should require little or no retuning either.

Please let us know 12 months from now if the Sniper system has proven to be "just turn the key and go", or if it demands regular re-tweaking. Very nice write ups.

 

[MoparCarGuy]

Following up on my Holley Terminator X Stealth 4150 installation. This project was a lot of work but has been the best tuning improvement ever for my Cuda. The timing control of the Hyperspark ignition and distributor worked perfectly from the start <<pun intended>>. Here is final result and throttle response is instantaneous. I will post a new thread with more installation pictures and some lessons learned very soon.

 

[SRKlegin]

Man, This by far the most informative post Ive seen in a long while. Thank you for sharing. I would really like to have you email me this when My 340 is in I can flip through the pages and get this done. Please PM me, sir.

 

[ChallengerGary]

Great thread. I have been trying to decide whether I want to go with a modern Hemi or a LA340 for my 1971 Challenger. I have a buddy with a rebuilt 340 sitting on a shelf that he is willing to sell me but I really want fuel injection. This may push me in the direction of going with the 340...

 

[ChallengerGary]

Great thread. I have been trying to decide whether I want to go with a modern Hemi or a LA340 for my 1971 Challenger. I have a buddy with a rebuilt 340 sitting on a shelf that he is willing to sell me but I really want fuel injection. This may push me in the direction of going with the 340...

Well, my decision has been made for me - my buddy is giving me the 340! He says he finally realized that he is never going to use it and wants me to enjoy it

 

[Russ Knight]

I'm dredging here, but man what a great thread! If the author is still around, thank you, sir!

 

[rklein71]

I was determined not to mount the coil to the firewall, so I spent a good part of the day fabbing a mount using the coil mounts on my RPM Air-Gap manifold.

Very similar to how I mounted my coil on my LD340 manifold for my Hyperspark coil.

 

[Russ Knight]

Very similar to how I mounted my coil on my LD340 manifold for my Hyperspark coil.

I was considering a six pack or single 4 barrel for my 340, but I'm leaning this way now.